Why is it so difficult to get an invoice for the amount paid?

The payment system is really unclear. Where do I find an invoice which shows how much I paid in total, which includes the service and the fee? This platform is so difficult to use and understand, it seems like some PPH have gone to extraordinary lengths to make sure buyers cannot find their invoices for accounting purposes which shows the total amount including the fees.

All very confusing, and a big deterrent for continuing to use the services.